For two years the mussels have been growing on long-lines placed in the idyllic Sankt Anna archipelago on the Swedish east coast. Some mussels were harvested in December 2017, and now it was finally time to harvest the remaining yield.
The farm was set up as a research project to find out what environmental impact the mussel farm would have on the surrounding waters. It is well known that mussels act as natural filters by feeding on phytoplankton, effectively removing nutrients from the water body, thus increasing water clarity.
Finding a suitable location is key for a high yield. Therefore, Mats Emilsson, local fisherman and entrepreneur, was recruited to choose an appropriate bay, tools and ropes for the mussel farm.
Mats’ efforts paid off. When putting out 24000 m ropes on 4 hectares water surface, he expected to harvest around 20-30 tons mussels. So far, 65 tons have been harvested, and the total is estimated to around 87 tons, more than double the expected yield.
During harvest, a harvest barge with all the equipment is brought out to the mussel cultivation. The ropes are then fed into a machine on the barge which scrapes off all the mussels before the rope is let back into the sea. Slowly but surely, all ropes are “cleaned” from mussels by the machine. Depending on the weather 5 tons of mussels can be harvested per day, for 50 tons it will take approx. 10 full working days.
The first 15 tons of mussels that were harvested in December last year were sent to a biogas plant nearby. The 50 tons harvested some weeks ago was sent to a farmer to be used as fertilizer on his land. The remaining mussels will stay on the lines to monitor the environmental impact of older mussels, for example on the sediment, and whether the mussels might grow even bigger.
As part of a cross-border cooperation within the Baltic Blue Growth project, a small batch has also been sent to another project farm in Vormsi, Estonia, for further experiments.
Want know more about what the Sankt Anna farm looks like and how the mussels are harvested? Watch the video on the harvest this spring
Listen to an interview with mussel farmer Mats Emilsson on Swedish radio about the harvest (in Swedish)